This invention relates generally to a solar energy collector system, and more particularly to a system and method for collecting solar radiant energy for converting to heat energy for a practical use.
Solar energy collector systems typically comprise a plurality of vacuum jacketed tubular collector elements. Each tubular collector element is sealed at its ends, contains a volatile fluid therein, and is in contact with a solar absorber. The solar absorber converts solar radiant energy to heat energy. The solar absorber transfers the heat energy to the tubular collector elements, which causes fluid in the tubular collector elements to vaporize. A pressure difference between the two ends of the tubular collector elements drives the vapor towards a cooler condenser portion of the collector element. The condenser portion is in contact with a heat sink. In the condenser portion of the collector element, heat is conducted from the vapor of the fluid inside the collector element to the heat sink outside of the collector element. The lower temperature of the vapor due to conduction of the heat from the vapor to the heat sink results in condensation of the fluid in the collector element. The condensed fluid then flows downward from the condenser portion of the collector element wherein solar energy is again absorbed to evaporate the fluid and continue the cycle.
In one application, the tubular collector elements are operably connected in a manifold, which serves to distribute and collect a working fluid, functioning as the heat sink. The working fluid is circulated for heating around the condenser portions of the tubular collector elements for removal of thermal energy absorbed by the collector elements. The tubular collector elements transfer the absorbed solar energy to the working fluid for storing the collected thermal energy, or for transferring the energy to a location where it can be put to practical use.
Developmental efforts relating to evacuated tubular collector elements has been directed to improving the efficiency of removal of the absorbed thermal energy. For the foregoing reasons, there is a need for an improved system and method for the removal of the thermal energy absorbed by evacuated tubular collector elements.